Any recommendations on where to find old CPU heatsinks and fans? Or recommendations on how to best keep COB LED cool

Bonjour VHS folks!

For the last few years we’ve been using a cheap LED grow light (~25w) we bought at Costco to start seedlings in the spring and to grow things that don’t grow so well outside (like thai basil). Considering how successful it has been, a while back I ordered a pack of COB LED with the intention of building a little grow room with a little more power… and the COBs have been sitting in their package since. I ordered the 10W COBs thinking I might get away with passive cooling from old CPU heat sinks and use the fans if needed.

I’m hoping to keep cost to a minimum. Does anyone know if perhaps some of the recycling places might allow us to grab old PCs or parts from them? Otherwise I’m planning to go check Free Geeks when I have a chance.

I’m also open to other suggestions if anyone has experience with this… I’m no expert in any of this.

I’d be interested in seeing pictures of your setup!

It’s plausible that you’d be able to get away with passive cooling for those COBs. The only way to know for sure is to try it and monitor the heat for a bit. VHS used to have a bunch of old heatsinks (with fans attached), but that was around a year ago, I’m sure they’ve been scrapped by now. Sometimes North Star Metal has entire skips full of old heatsinks. I’d check there first, and then it’s right near FreeGeek / The Hackery too if that doesn’t work.

You might not even need proper heatsinks, just a big chunk of metal.

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Very cool you are growing food! This isn’t COB specific but I know one member who used an old metal cooking pan as a heat sink and light deflector for some grow lights. So - seconding Jarrett there on the ol’ big chunk of metal. You may be able to find some old aluminum pans at Value Village (which is also up near FreeGeek on Hastings).

If you come up with a good solution, please let us know, as I’ve dropped these kits at VHS for anyone to do, and if you fully populate them (or get anywhere close to fully populated) they’ll need some heat sinking:

Last time I was at the hackspace (about a week ago) , there were a couple of old CPU heatsinks on the freecycling shelf. Might be worth a look?


Thanks for the suggestions, I’ll check them out when I have a chance. I totally forgot about the Hackery and it’s not too far. The idea of using old aluminum cookware is interesting too. I do have a heat probe that I should be able to use to monitor the temperature.

I’m unfortunately not a current member of VHS. I like the idea but for the few hours I’d use it in a year getting a membership doesn’t make much sense. Most of the time what I need is a tool for a few minutes or hours to fix something broken around the house. For example in the next few months I’d like to replace the cells in a couple of old battery packs and I wish I could just borrow a spot welder for 15 minutes…

I did visit a few years ago on an “open night” to use a heat gun to replace a dead component on my old TV main board. That repair lasted about 6 months… until something else failed that wasn’t worth fixing. I can’t remember the name of the member who helped me at the time but I was very grateful.


There’s a bin of heatsinks on the very bottom of the electronics shelf . Help yourself to anything that looks useful to you.


We love having you here even as a non-member. We know it can be difficult to justify a membership when usage would be occasional, so please don’t make yourself a stranger at our open nights and do feel free to use what would otherwise become waste.

If you get to the point where you are taking home a lot of materials, just throw whatever you think is fair that you can afford in the donatio[n] bin at the lockers in the chill out area.

We’d much rather make sure you feel welcome to VHS over collecting dues. Hope to see you in-person one day.

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Check out free geek too. If you meow at the hackery staff. They will give you discount or stare at you weirdly.


You have an amazing community here, thank you so much! Perhaps I’ll come by at the next open house.